1. Field of the Invention
The present invention is related to a reticle pod, and more particularly, to a reticle pod with a plurality of supporting pieces respectively and suspendingly disposed at each corner of the inner surface of the upper cover and the lower cover for ensuring the stability of the photomask stored in the reticle pod and preventing from unnecessary collisions that will lead to displacement or damage of the photomask stored in the reticle pod.
2. Description of the Prior Art
In the rapidly developing semiconductor technology, optical lithography plays an important role and wherever pattern definition is conducted, optical lithography is requisite. In the application of optical lithography relating to semiconductors, a designed circuit pattern is used to produce a light-transparent photomask with a particular shape. With the principle of exposure as basis, after a light source passes through the photomask to project on a silicon wafer, the circuit pattern formed on the photomask can be exposed onto the silicon wafer. Since any dust (such as particles, powders or organic matters) can cause negative impact on the quality of such projected pattern, the photomask used to produce the pattern is required to be kept with absolute cleanness, and therefore in ordinary wafer process, clean room environment is provided to prevent from contamination of particles in the air. However, the status of absolute cleanliness still cannot be achieved in the clean room currently in use. At present, anti-contamination reticle pod is used in the semiconductor process for storing and transporting the photomask to ensure the cleanliness of the photomask.
However, when the reticle pod is used to store and transport the photomask, a plurality of supporting pieces need to be disposed in the reticle pod for supporting and propping up the photomask. When the photomask is placed in the reticle pod for storage, the supporting pieces are in direct contact with the photomask and therefore friction between the supporting pieces and the photomask occur more easily and will then generate static electricity that leads to damage of the photomask; when the photomask is placed in the reticle pod for being transported, the vibration generated in the transporting process will cause damage or crack of the photomask more easily. How to provide the supporting pieces with both the merit of resistance to damage from static electricity and the merit of anti-vibration thus becomes a critical subject.